Hypodermic syringes



Oct. 23, 1956 l' s, N. BLACKMAN 2,767,710

` HYPODERMIC SYRINGES Filed Nov. 6, 1952 Ti lz..

United States Patent HYPODERMIC SYRINGES Seymour N. Blackman, Teaneck,N. J., assignor to Premo Pharmaceutical Laboratories, Inc., SouthHackensack, N. J., a corporation of New York Application November 6,1952, Serial No. 319,133 Claims. (Cl. 12S-218) This invention relates tohypodermic syringes, and more particularly to syringe tips.

Conventionally, a syringe is made from glass in one piece with thebarrel. The ditiiculty with such a tipV is that it has to be very finelyand accurately ground to insure a tight frictional iit with the hub of aneedle. Besides being expensive to make, such tips are brittle andeasily broken in use. Glass tips have the advantage, however, of beingeasy to clean since, being integral with the barrel, they have no hardto reach interstices where matter can lodge.

Metal syringe tips have been found to be much easier to fabricate in aproper size to receive the hub of a needle; of course, they also areless susceptible to break-age. But matter invariably lodges in the jointbetween the metal tip and glass barrel. Since the metal tip ispermanently secured to the barrel, metal tip syringes cannot bethoroughly cleaned and have to be discarded after being used la fewtimes and sometimes after only a single use.

It is an object of the present invention to provide a metal tippedhypodermic syringe having all the advantages of glass tipped and metaltipped syringes but the disadvantages of neither.

it is another object of the present invention to provide a hypodermicsyringe of the character described which can be easily `and thoroughlycleaned.

It is another object of the present invention to provide a hypodermicsyringe of the character described which is simple and inexpensive toproduce in mass production.

It is another object of the present invention to provide a hypodermicsyringe of the character described which is rugged and long-lasting.

Other objects of the present invention will in part be obvious and inpart will be pointed out hereinafter.

The invention accordingly consists in the features of constructions,combinations of elements and arrangements of parts which will beexamplitied in the devices hereinafter described and of which the scopeof application will be indicated in the appended claims.

ln the accompanying drawings in which are shown the various possibleembodiments of the invention:

Fig. 1 is a side view of a hypodermic syringe constructed in accordancewith the present invention;

Fig. 2 is an enlarged exploded view of the tip of the syringe shown inFig. l;

Fig. 3 is -an enlarged sectional view taken substantially along the line3 3 of Fig. l;

Fig. 4 is a sectional view taken substantially along the line 4-4 ofFig. 3;

Fig. 5 is a fragmentary plan view of a hypodermic syringe embodying amodied form of the present invention;

Fig. 6 is an enlarged sectional view taken substantially along the line6 6 of Fig. 5; `and Fig. 7 is a sectional View taken substantially alongthe line 7-7 of Fig. 6.

Referring now in detail to the drawings, and more particularly to Figs.1 4, the reference numeral 10 de-` notes a hypodermic syringe having ametal tip 12 embodying the present invention. The syringe includes aglass barrel 14 having an integral cylindrical plug 16 at its bottom.The bore of the barrel is smoothly ground to s lidably receive asimilarly ground plunger 18.

A metal tip 20 is integral with the bottom of an opentopped tubularsocket 22 adapted to permanently frictionally engage the glass plug. Acentral passageway 24 in the plug is aligned with a central passageway26 in the tip.

It is between the top surface 28 of the base of the socket and theparallel under surface 30 of the glass plug that matter lodges. Washingthe syringe cannot dislodge this material.

Pursuant generally to the present invention, a ilexible resilient washer32 composed, for example, of polyamid resins, e. g. nylon, is sandwichedbetween said top surface 28 and under surface 30. Said washer has anaperture 33 registered with the passageways 24, 26 and of the same orbarely larger diameter. When the socket is assembled on the plug, thewasher is compressed thereby preventing material fromcollecting betweensaid opposed surfaces. No matter can be caught between the washer andthe surfaces it abuts because the elasticity of the washer and thecompression under which it is held create a tight tit between saidwasher and surfaces. Such a tit could not be obtained practicablybetween the glass surface 3@ and metal surface 28.

Although a planar top surface 23 will accomplish the objects of thepresent invention, in the illustrated syringe said surface is providedwith an upstanding narrow annular stub ilange 34 around the top of thepassageway 26. When the socket is tightened on the glass plug, theflange is forced into the washer, ensuring a very tight t between thewasher, socket and plug with a localized high pressure in the region ofthe flange. If desired, the upper end 35 or" the passageway in the metaltip may be flared somewhat to allow for tolerances in the size andposition of the opening in the washer. It will be observed that this-arrangement does not form cracks from which material cannot be flushed.

The metal tip removably and frictionally engages the Luer hub 36 of ahypodermic needle 38, the tip being tapered to match the standard hubcavity.

In the modied form of the invention shown in Figs. 5-7, the metal tip isidentical to that already described, except for the addition of a needlelock. Said lock constitutes a skirt 40 on the socket in which the hub ofthe needle is received. The inside of the skirt includes a thread 42with which corners 44 on the needle hub mesh.

Thus it will be seen that there are provided devices which achieve allthe objects of invention and are well adapted to meet the conditions ofpractical use.

As various possible embodiments might be made of the above invention,and as various changes might be made in the embodiment above set forth,it is to be understood that all matter herein described, or shown in theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

Having thus described the invention, there is claimed as new and desiredto be secured by Letters P-atent:

1. In a hypodermic syringe having a glass barrel with a plug at itsbottom, said barrel having an aperture at its bottom extending throughsaid plug in a direction axially of the barrel, Ia metal socket with anintegral tip, said socket having an aperture extending through said tipin an axial direction, said plug being permanently secured in saidsocket with said barrel and socket apertures in alignment, the upper endof the aperture in the socket being larger than the lower end of theaperture in the barrel, and a ilexible resilient washer of syntheticplastic compressed between said plug and socket, said washer having anopening therethrough, said opening in the washer being in alingementwith the barrel and socket apertures, the aperture at the upper end ofthe tip of the socket being larger than the opening in the washer andthe opening in the washer being larger than the lower end of theaperture in the barrel.

2. A combination as set forth in claim 1 wherein the socket has a narrowannular stub Harige around the top of the aperture therein.

3. A combination as set forth in claim 2 wherein the aperture in thesocket is ared at its top.

4. For use with a hypodermic syringe having an apertured glass plug anda ilexible resilient washer of synthetic plastic disposed therebelow,said washer having an opening therethrough, the opening in the washerbeing larger than the lower end of the aperture in the barrel, a. metalsocket permanently secured to the plug and holding the washer undercompression, said socket having an apertured tip extending therefrom,the upper end of the aperture in the tip being larger than the lower endof the aperture in the plug, and a narrow annular stub flange in thesocket around the top of the aperture in the tip, the upper end of theaperture in the socket being larger than the opening in the washer.

5. For use with a hypodermic syringe having an apertured glass plug anda flexible resilient washer of synthetic plastic disposed therebelow,said washer having an opening therethrough, the opening in the washerbeing larger than the lower end of the aperture in the barrel, a metalsocket permanently secured to the plug and holding the washer undercompression, said socket having an apertured tip extending therefrom,the upper end of the aperture in the tip being larger than the lower endof the aperture in the plug, and a narrow annular stub ange in thesocket around the top of the aperture in the tip, the aperture in thetip being flared at its top, the upper end of the aperture in the socketbeing larger than the opening in the washer.

References Cited in the tile of this patent UNITED STATES PATENTS1,471,644 Bandman Oct. 23, 1923 2,520,092 Fredrickson et al. Aug. 22,1950 2,656,836 Hickey Oct. 27, 1953 FOREIGN PATENTS 494,921 GreatBritain Nov. 3, 1938

